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Advances in the field-theoretic understanding of pion production in nucleon-nucleon collisions

V. Lensky·J. Haidenbauer·C. Hanhart·V. Baru·A. Kudryavtsev·U. -G. Meißner
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Abstract

We study the production amplitude for the reaction $NN\to NNπ$ up to next-to-leading order in chiral perturbation theory. We show that the irreducible chiral loops at this order exactly cancel those terms that arise from the off-shell parts of the $πN$ rescattering vertex. This cancellation is required for formal consistency of the whole scheme. The net effect of the inclusion of all next-to-leading order loops is to enhance the leading rescattering amplitude by a factor of 4/3 compared to phenomenological studies, bringing its contribution to the cross section for $pp\to dπ^+$ close to the experimental value.

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V. Lensky, J. Haidenbauer, C. Hanhart, V. Baru, A. Kudryavtsev, U. -G. Meißner. 2006-09-04. Advances in the field-theoretic understanding of pion production in nucleon-nucleon collisions. https://doi.org/10.1142/s0217751x07035902

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